There are various types of mobile devices which are used for handling, or manipulating heavy loads. Many of them, like hydraulic excavators, have a chassis on which a boom member is pivotally mounted, there is an arm member pivoted at the free end of the boom, and an excavator bucket or other hydraulically operated apparatus is at the free end of the arm. Hydraulically operated mechanisms mounted on such devices in place of excavator buckets include tree harvesting devices, log grapples, hydraulic impact hammers, pile drivers or earth compactors, etc.
Such devices are usually used in very rough environments where the hydraulic conduits on the boom and on the arm are subject to severe stresses; and particularly with such attachments as tree harvesters and log grapples the boom and the arm may be subjected to severe torsional strain which can damage the conduits. In addition, the heavy vibrations developed in such apparatus cause metal fatigue in the conduits and loosen conduit connections. These factors, plus the rough conditions of use, complicate the development of appropriate conduit mountings for the boom and the arm. The rigid hydraulic conduits must be firmly supported, but they must be free to move slightly in all directions relative to the boom, or the arm, as the case may be, to minimize conduit damage and connection problems in operation.